--- a/src/tree.c	Sun Jan 05 13:44:02 2025 +0100
+++ b/src/tree.c	Sun Jan 05 13:54:09 2025 +0100
@@ -42,6 +42,13 @@
 #define cx_tree_ptr_locations \
     loc_parent, loc_children, loc_last_child, loc_prev, loc_next
 
+#define cx_tree_node_layout(tree) \
+    (tree)->loc_parent,\
+    (tree)->loc_children,\
+    (tree)->loc_last_child,\
+    (tree)->loc_prev,  \
+    (tree)->loc_next
+
 static void cx_tree_zero_pointers(
         void *node,
         ptrdiff_t loc_parent,